I recently did it from the top, just rock the engine as far forward as you can get it(I used ratchet straps to the rad support) and you can lean over and get em with a 6-sided wrench and a "persuader" like another wrench or something, and put some antisieze on em, so next time is easier......
On a side note, the fisrt time I removed them was from the bottom, 18" 3/8 drive breaker bar, 3 extensions, one universal joint extension and a deep socket, and it came out ok, they are far enough up that they don't get nearly as much road crap as the cat to resonator bolts get
